US Chemical & Toxic Substances Management Regulatory System

Section 6 of the Toxic Substances Control Act (TSCA) grants EPA authority to regulate the manufacture, processing, distribution, use, and disposal of an existing chemical substance where EPA determines it presents an "unreasonable risk." Since the 2016 TSCA amendments (the Frank R. Lautenberg Chemical Safety for the 21st Century Act), EPA has progressively conducted risk evaluations of existing chemicals and finalized phased prohibition and restriction rules for substances of high concern. Around 2024, EPA finalized risk management rules in succession for major substances including methylene chloride, N-methylpyrrolidone (NMP), trichloroethylene (TCE), perchloroethylene (PCE), and phenol, isopropylated phosphate (3:1) (PIP (3:1)). In addition, regulatory action under Section 6 is proceeding for carbon tetrachloride (CTC), 1,4-dioxane, and chrysotile asbestos. Under the Trump administration, these finalized rules are also undergoing substance-by-substance reconsideration—including compliance deadline extensions and relaxed enforcement posture—with the latest developments for each substance addressed in the Level 3 child cards below.

Significant New Use Rules (SNURs) established by EPA under TSCA Section 5(a)(2). The system requires companies to submit a Significant New Use Notice (SNUN) to EPA and complete a 90-day review before manufacturing, importing, processing, or using a designated chemical substance for a use or quantity that qualifies as a "significant new use" (SNU).

The PFAS reporting rule issued under TSCA Section 8(a)(7) in October 2023 was originally scheduled to open for reporting in November 2024, but was delayed to July 11, 2025 due to budget and system development constraints. In May 2025, however, EPA further delayed the reporting window to "April 13, 2026 through October 13, 2026." Subsequently, in November of that year, EPA published a proposed substantive amendment to the rule. The amendment centers on three elements: (1) establishing a new "de minimis concentration exemption" excluding PFAS present below 0.1% by weight in mixtures from reporting; (2) adding several exemptions related to matters such as imported articles; and (3) resetting the reporting window to "2 to 5 months after the effective date of the amended final rule." As of August 24, 2026, the amended final rule has not yet been published, but EPA has concurrently indicated an interim operational approach setting the reporting window to open on "January 31, 2027 (or 60 days after the effective date of the amended final rule, whichever is later)."